Inorganic microporous ilnk-jet recording media is in wide use today for producing high quality images with fast print speed and rapid dry time. However, general exposure of inorganic microporous media based images to atmospheric contaminants can result in air fade, which physically alters the media and changes or degrades the image quality. It is desirable to enhance the permanence and quality of the images.
Prior solutions for addressing the problem of air fade include laminating a plastic sheet or transferring a polymer film over a printed image using thermal overcoat transfer. Lamination adds a second step to the printing process and the thermal overcoat transfer requires the use of a second web with the thermal overcoat material coated on it. Both of these approaches add complexity and cost.
Materials such as latexes having high glass-transition temperatures Tg (95° to 110° C.) and large particle sizes on the order of 500 nanometers and above have been fused onto the surface of a printed image to provide image protection (water resistance, light fade resistance). However, this approach requires high temperature, above the glass transition temperature (Tg) of the latex, and pressure to heat and fuse the material.
Specific prior art attempts using latex, fused on an ink jet substrate have been made. However, even though coatings containing latex have been used in inkjet for some time, very little development has been made in using latexes for improving image permanence (specifically, air fade resistance) of photo quality ink jet images using inorganic microporous ink receiving layers.
Thus, what is needed is a process to enhance the permanence and quality of images printed on ink-jet recording media that avoids the problems of the prior art and provides a media with excellent air fade resistance.